Can someone help me? I purchased these fans the other day and they seem to only have one speed when plugged into the motherboard with the 3 pin connector. I've been using bios to change the fan speeds but it doesn't seem to work with these fans. Am I doing something wrong? My motherboard is the Asrock Z75 pro3.

Is there such a thing as "Q-Fan" in your BIOS? Asus boards as far as my experience goes can vary the fan voltage and can control speed this way. On my old Rampage Extreme there were 3 such fan headers and my current Sabertooth 990FX has many more. Also of note is that even though Sabertooth has some 4 pin headers they still work with 3 pin fans.

Does your motherboard have 3-pin headers or 4-pin headers? If they're 4 pin headers, they're usually PWM controllers by default. You need to enable voltage control in your motherboard, if it has it. If not, you have to convert the PWM into a voltage signal (using some simple circuit tricks).

Does your motherboard have 3-pin headers or 4-pin headers? If they're 4 pin headers, they're usually PWM controllers by default. You need to enable voltage control in your motherboard, if it has it. If not, you have to convert the PWM into a voltage signal (using some simple circuit tricks).

I have one connector that is 4-pin and three 3-pins. I'll look into the voltage controls when I get home later. I'm assuming that voltage controls only work on the 4 pin headers? The fans are 3-pin connectors, would that matter?

3 pin fans only use the first three; they have no PWM pin for control. So the only way you can change the speed of the fan is to change the PWR input. If it was 4 pins, you could control it with PWM.

Almost all motherboards will have PWM control, but that does not work for 3 pin fans. Instead, you have to hope that your motherboard has onboard voltage control (which varies the voltage through the PWR pin).

PWM is for controlling 4 pin fans using 4 pin headers
Voltage control is for controlling 3 pin fans, using either 3 pin headers or 4 pin headers, depending on the design of the motherboard

I think my problem has more to do with the fans then it does the motherboard. I have another fan inside of my case that can be controlled with the Bios fan settings but they can't control the new fans that I purchased, specifically the Nexus Real Silent fans. I just finished downloading and trying the Asrock Extreme Tuning Utility and it doesn't work on the Nexus fans either. What circuit tricks can I do short of buying a new 7v cable?

Okay. I think I narrowed the problem down a bit more. It seems that there are only two 3-pin headers that can be controlled by the motherboard. They are both 3-pin. Two others are 4-pin headers. The last one is pwr_fan1 and they are all set to max speed for some reason. The pwr_fan1 is a 3 pin header.

^^^ My ASRock board is like this as well. After contemplating how to have it work my fans how I wanted, including a combination of software control and some Zalman fan mates, I finally gave up. I wanted a bunch of case fans and wanted them all at low noise / low RPM, and there wasn't a clean way to do it. I ended up just getting one of these:

I will say I love it. 5 fans at any speed you want, warning beeps to let you know if any go to 0 RPM, and includes temperature leads (you can set temp thresholds that'll kick up the fan speeds as needed to drop a temp back down).

If you have an extra 5.25" external bay and also don't mind throwing a few bucks at the problem, this will do just about whatever you want.